package gdax

import (
	"github.com/kcotugno/tacitus"

	"encoding/json"
	"net/http"
	"strconv"
	"strings"
	"time"
)

const (
	endpoint = "https://api.gdax.com"
)

type PublicClient struct {
	client http.Client
}

func NewPublicClient() *PublicClient {
	c := PublicClient{}
	c.client = http.Client{Timeout: 30 * time.Second}

	return &c
}

func (c *PublicClient) GetTradesBefore(product string, id int) ([]tacitus.Trade, error) {
	url := strings.Join([]string{endpoint, "products", product, "trades"}, "/")
	url = strings.Join([]string{url, "?after=", strconv.Itoa(id)}, "")

	resp, err := c.client.Get(url)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	results := make([]tradeResponse, 0)

	decoder := json.NewDecoder(resp.Body)
	if err = decoder.Decode(&results); err != nil {
		return nil, err
	}

	trades := make([]tacitus.Trade, 0)
	for _, t := range results {
		var trade tacitus.Trade

		trade.TradeId = t.TradeId
		trade.Product = strings.ToUpper(product)
		trade.Price = t.Price
		trade.Size = t.Size
		trade.Timestamp = t.Time

		switch t.Side {
		case "buy":
			trade.Buy = true
		case "sell":
			trade.Sell = true
		}

		trades = append(trades, trade)
	}

	return trades, nil
}